Generally, an electric car is configured to run by taking in electric power from an overhead catenary with a power collector, and by driving an electric motor using the electric power from the overhead catenary.
In recent years, because performance of electric-power storage elements such as a secondary battery and an electric double-layer capacitor has been improved, developments of systems that drive an electric motor by using electric power of these electric-power storage elements have been progressed by installing these electric-power storage elements on the electric car.
As types of these systems, a partial overhead-catenary free system, a complete overhead-catenary free system, and the like are being studied. According to the partial overhead-catenary free system, from a scenery viewpoint, an overhead catenary is removed from a part of a section of an existing electrified route, or only a route-extended portion of an existing electrified route is set as overhead catenary free. When an electric car runs in a section having an overhead catenary, the electric car uses electric power from the overhead catenary, and when the electric car runs in an overhead-catenary free section, the electric car runs using electric power from electric-power storage elements. According to the complete overhead-catenary free system, overhead catenaries are removed from all routes, and an electric car runs using only electric power from electric-power storage elements. A power source for an electric charge and an overhead catenary are provided at only terminal stations and intermediate stop stations. Electric power taken in from this overhead catenary is charged to the electric-power storage elements (for example, Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-open No. 2006-238652
An example of running of an electric car in a partial overhead-catenary free system or in a complete overhead-catenary free system as explained above is explained. In a section having an overhead catenary, an electric car raises a pantograph as a power collector, and runs as an existing electric railway by collecting electric power from an overhead catenary as an overhead conductor portion. In a section having no overhead catenary, the electric car lowers the pantograph, and runs using electric power of electric-power storage elements. To complement electric power consumed in the section having no overhead catenary, the electric car raises the pantograph and quickly charges electric power to the electric power storage elements from the overhead catenary provided to charge electric power, during a few dozens of seconds to a few minutes while the electric car is stopped at a station and the like.